Mars Rover Sets Endurance Record

Look to the southwest in tonight’s sky, and if it’s a clear night, you’ll see the ruddy dot of Mars just to the right of the bright star Regulus, which will sit almost directly above the first-quarter moon.

Once you’ve found Mars, send a mental high-five in that direction: There’s a little robot trundling across the surface of that distant, dusty planet, and it’s just set a world record.


“Eat my dust, Viking 1!” Opportunity left these tracks in the Martian soil on May 8.

—Picture courtesy NASA/JPL-Caltech

As of today, the Mars rover Opportunity has surpassed the endurance record held by the Viking 1 lander for longest time spent working on the red planet: 6 years, 116 days.

That’s not bad, considering that Opportunity and its twin rover Spirit were each supposed to last just 90 days.

Of course, Opportunity won the title on a technicality.

Spirit landed and started its operations about three weeks before its twin. But Spirit, which has been stuck in a crater, ceased communications on March 22.

With the short, cold days of Martian winter closing in, engineers knew that Spirit was headed for hibernation mode, because the solar-powered rover was running low on energy.

This in itself wouldn’t be too scary, since the rovers were designed to hibernate. While sleeping, the craft shut off most activities—including communications with Earth—to reroute all available power to staying warm and keeping their batteries charged.

The idea is that, when winter nears, mission managers park the rovers and position them to soak up as much of the limited sunlight as possible. That keeps them fed while they sleep, so that when spring and sunshine return, they wake up and get back to work.

But in Spirit’s case, the team was struggling to maneuver the rover, which has been mired for months in the crater’s soft sand. In the end, they couldn’t get the bot into optimal position before it ran too low on juice and stopped talking.

That means there’s a chance Spirit will starve to death in its sleep.

Now that Mars’s winter solstice has passed, the team hopes Spirit will build its energy supplies and wake back up. If [when?] it does, that rover will claim the endurance title.

In any case, Opportunity definitely has Viking 1 beat. That lander arrived on Mars in July 1976 and kept on truckin’ until November 1983.


Carl Sagan, of “Cosmos” fame, stands with a scale model of a Viking lander in Death Valley, California.

&#8212Picture courtesy NASA/JPL

Well, not literally trucking: landers don’t move. Still, the Viking mission—which included two landers and orbiters to match—gave humans an unprecedented vision of the Martian surface, sending back high-resolution color pictures of the windswept terrain as well as a suite of data on Mars’s soil chemistry, atmosphere, and geologic history.

Bear in mind, btw, that this is the record for a craft on Mars’s surface … The Mars Global Surveyor (September 1997 to November 2006) worked in orbit around Mars for more than nine years.

The currently operational orbiter Mars Odyssey (October 2001 to present) looks good for beating that record later this year.

And don’t forget that the two Voyager probes, launched in 1977, are still sending back science data from the very edges of the solar system after more than 30 years on the job.

It’ll be interesting to see how long the Mars rovers can keep functioning. Although winter-bound Opportunity is saving energy by taking breaks as it drives toward its new target, Endeavour Crater, the rover shows no signs of slowing down in the long run.

Not to mention, with the future of U.S. manned space missions being hotly debated, it’s not likely we’ll run out of uses for the hardy rovers anytime soon. So cheers to you, Opportunity, and here’s hoping Spirit hasn’t yet decided to take the metaphorical gold watch.

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